Croft



(No Model.

J. s. BANG ROFT. MBANS FOR OPERATING THE DIE HEADS 0P BOLTTHREADING MACHINES. No. 417,659. Patented Dec. 17, 1889.

FIG I FIG. 4.

UNITED STATES PATENT OFFICE.

JOHN SELLERS BANCROFT, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOH TO THE WILLIAM SELLERS & OOMPANY,INCORPORATED, OF SAME PLACE.

' MEANS FOR OPERATING THE DIE-HEADS OF BOLT-THREADING MACHINES.

SPECIFICATION forming part of Letters Patent No. 417,659, dated December 17, 1889.

Application filed October 18, 1889. Serial No. 327,428. (No model.)

To all whom it may concern.-

Be it known that I, JOHN SELLEEs BAN- CROFT, of the city and county of Philadelphia, and State of Pennsylvania, have invented certain new and useful Improvements in Bolt-Threading Machines, of which the following is a specification.

My present invention is an improvement upon the form of bolt-machine patented to William Sellers December 1, 1857, and relates to the mechanism for rotating a cam-box about acentral revolving die-box for the purpose of opening and closing the cutting-dies. In the Sellers machine above referred to the dies in closing were always brought accurately to the same position, so that the threaded bolts were always of the same size; but the shocks resulting from the sudden starting and stopping of the large gear-wheel and attached parts operating the cam-box made it unsafe to run the machine at as high aspeed as the dies were capable of running, and hence the output of the machine was too low.

Other devices have been used for the purpose of operating the cam-box on bolt-threadin g machines and arranged to avoid the shocks incident to the type of machine above referred to; but the avoidance of shock has hitherto been obtained at the risk of inaccuracy in closing the dies.

It is the object of my present invention to provide a means for operating the cam-box of abolt-threading machine which shall be certain and accurate in its action, entirely independent of the speed of the rotating parts, and at all times under the control of the operator, and to these ends my invention consists in a die-box, a driving-wheel adj ustably secured thereto, and a cam-box rotatable about the axis of the die-box and adapted to be positively driven by an abutment on -the driving-wheel, in combination with a sliding sleeve coupled to the driving-wheel by keys parallel with the axis of rotation and coupled to the cam-box by helical keys or screw-threads, whereby the longitudinal movement of the sleeve in one direction will rotate the cam-box away from the driving abutment to open the dies, and movement in the opposite direction will rotate the cambox back against the driving abutment, so

that the closing-cams will stand in precisely the same relation to the die-box as before and the bolts threaded will all be of precisely the same diameter.

In the accompanying drawings, which form part of this specification, Figure 1 shows an elevation, partly in section, of a die-box, cambox, driving-gear, and sliding sleeve. Fig.2 is an end View of the die and cam-box with the cover-plate removed. Fig. 3 is a section through Fig. 1 on the line X X. Fig. 4 is a horizontal section through the hub of the driving-wheel and the sliding sleeve, showing keyway.

A A is a die-box, shown with four slots, in which the dies 13 B fit, so as to slide easily in a radial direction when operated, as hereinafter described. The die-box is formed with a sleeve, which has firmly secured to it the index-arm O. The driving-Wheel D is mounted so as to turn. freely upon the sleeve, and is secured to the index-arm O by the bolt a at any desired angle of revolution, graduations being provided on the wheel for .this purpose, the index-arm or driving-wheel, or

both, being provided with a curved slot to permit the necessary movement of the bolt. The hub D of the wheel D is cut away on the end toward the die-box for rather more than half its circumference, leaving a radial abutment b, which engages with a corresponding abutment or shoulder c on the end of the sleeve of the cam-box, as shown in Fig. 3,t11e motion being in the direction of the arrow, the wheel D being the driver.

The cam-box E is supported at M in a suitable bearing and forms itself the bearing for the die-box A, which turns freely within it. The cam-box E is provided with closing-cams G G, as shown, against the inner surfaces of which the dies B B abut, so as to be solidly held in position against the strain of cutting threads on bolts. The diesB B are provided with notches, which receive the opening-cams H H, fastened to, the cover-plate I, which is secured to the closing-cams G G. It will be seen from Figs. 2 and 3 that if the cam-boxE is rotated in the direction of the arrow relatively to the die-box A the dies will by the action of the opening-cams H H be moved outwardlyin theslots in the die-box, and the gage with shoulder a will be separated from the driving abutment Z2, and by continuing this relative rotation the dies will be. withdrawn Sllfl'lciently to clear the threads on a bolt cut by the dies, and if the cambox be rotated in the opposite direction until the shoulder a eoinesin contact with the abutment b the cams G G will stand in precisely the same relation to the die-box A as before, and the dies will therefore produce threads of precisely uniform diameter. By adjusting the relative positions of the driving-wheel D and theindeX-arm C by means of the bolt a the relative positions of the die-box and cam-box will be changed,with the effect of increasing or decreasing the diameter of the threadet bolt cut by the dies.

The rotation of the cam-box E relatively to the die-box A is accomplished by the sliding sleeve K, which fits easily upon the hub D of the driving-wheel D, and is forced to rotate with it by means of the keys L L, secured to the hub D and fitting easily in keyways in the inside of the sleeve K, as shown. The end of the die-box E is enlarged at F and provided with screw-threads, which en'- corresponding screwthreads formedin the interior of the sliding sleeve K. These threads are made of such steep pitch that endlong motion of the sleeve K will easily rotate the cam-box E. The keys L L project beyond the end of the hub D and are cut away so as to clear thetops of the threads formed on the enlarged portion F of the cambox E. The sliding sleeve K is provided with a groove f f, with which a handle or lever may engage for the purpose of moving the sleeve back and forth in any convenient It willbe observed that movement of the sliding sleeve K toward the cam-box will cause the cam-box E to rotate relatively to the die-box A in the direction of the arrow, Fig. 2, and the dies B B will be opened, so as to clear the thread of a bolt out by them, and that this motion may be made fast 01' slow and will not in any way depend upon the rotation of the various parts or the speed of rotation. Movement of the sleeve K toward the driving-Wheel D will rotate the cam-box in the opposite direction, so as to close the dies, and this rotation is arrested by the radial abutment 0 coming to rest against the abutment b on the hub of the driving-wheel D,when both cam-box and die-box will revolve together. The resistance due to the friction of the cam-box in its bearing holds these abutments b and c firmly together, so that the closing-cams G Gare always brought into a definite position relatively to the diebox A, and hence bolts cut by the dies B B will be of exactly the same diameter.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In a bolt-cutting machine, a die-box, a driving wheel adjustably secured thereto, and a cam-box rotatable aboutthe axis of the die-box and adapted to be positively driven by an abutment on the driving-wheel, in combination with a sliding sleeve coupled to the driving-wheel by keys parallel with the axis and coupled to the cam-box by helical keys, the combination being and operating substantial] y as described.

J. SELLERS BANCROFT.

Vitnesses:

HORACE W. SELLERS, J OHN L. PHILLIPS. 

